A physical model was developed to study bubble movement and distribution behavior in consideration of the coupled effects of electromagnetic brake (EMBr) and argon gas injection in a slab continuous casting mold with high casting speed. Mercury and argon gas were employed to simulate the molten metal and argon gas two-phase flow. The resistance probe was applied to study the gas bubble statistical behavior in the mold with and without EMBr under different argon gas flow rates. The effects of EMBr and argon gas flow rate on the local void fraction, number and pulse width of gas bubbles were investigated. The results show that when the magnetic field is imposed under a given casting speed, the distribution of gas bubbles in the mold changes, the floating up rate of gas bubbles increases, the penetration depth of gas bubbles becomes lower, and the number of gas bubbles reaching the narrow face of the mold decreases. The number of gas bubbles with wide pulse increases between the 1/4 width of the mold and the nozzle with EMBr or with the argon gas flow rate increasing.